Telephone-receiver.



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TELEPHONE RECEIVER.

(Application Bled Nov. 30, 1900.)

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No. 687,996. `Patanfd Dec. 3, 190|. v

, H. LIEBREICH. I

TELEPHONE RECEIVER. I'

{Application led Nov. 30, 1900) (No Model.) 2 Sheets-Sheet 2.

UNITED STATES PATENT OFFICE.

HANS LIEBREICH,` OF DETROIT, MICHIGAN.

TELEPHONE-RECEIVER.

SPECIFICATION forming part of Letters Patent No. 687,996, dated December3, 1901.

Application filed November 30| 1906. Serial No. 38,195. (Nd model.)

To all whom, it may concern,.-

Be it known that I, HANS LIEBREICH, a citizen of the United States,residing at Detroit,`

in the county of Wayne and State of Michigan, have invented certain newand useful Improvements in Telephone-Receivers; and Ido hereby declarethe following to be a full, clear, and exact description of theinvention, such as will enable others skilled inthe art to which itappertains to make and use the same.

My invention relates to improvements in telephone-receivers,and isparticularly adapted for the augmenting or increasing of the power ofthe tones or impulses received over telephone-lines.

It consists in a receiver having suitable diaphragms, a coil locatedbetween them, a core within the said coil carrying a series of permanentmagnets, the ends of the said magnets being arranged in suitableproximity to the said diaphragm to actuate the same, and means forconnectingv the receiver with the line-wires of the telephone.

It further consists in a receiver having one or more diaphragms and anoperating-core arranged in suitable proximity to the said diaphragm,said core comprising a split cylinder adapted to be magnetized anddemagnetized, a coil surrounding the said cylinder and connected withthe line-wires, and a series of magnets mounted within the cylinder foracting directly upon the diaphragm of the receiver.

It further consists in certain other novel constructions, combinations,and arrangements of parts, as willbe hereinafter more fully described,illustrated, and claimed.

In the accompanying drawings,Figure 1 represents a longitudinal centralsection through a receiver embodying the present invention. Fig. 2 is anenlarged sectional detailview of a portion of the said receiver, showingin a diagrammatical manner the action of the receiver-core upon thediaphragm. Fig. 3 is a detail cross section through the receiver showingthe diaphragm in a vibrated condii tion. Fig. 4 is a detailcross-section through the receiver showing the magnets forming the corethereof and the 4coils surrounding the same. Fig. 5 is a longitudinalcentral section through a receiver employing only one diaphragm. Fig. 6is a cross-section through the same, said section being taken throughthe Fig. 7 is an end elevation of the core and the magnets forming apart of the same. Fig. 8 is a diagrammatical view showing the manner ofconnecting the receiver with a telephoneline in which a transformer forinducing the efficiency thereof is employed. y

My improved receiver is constructed so that itmay be used in connectionwith any ordinary telephone-line; but it is especially efcient when usedin connection with a telephone-line employing a device for increasingthe power of the impulses sent'over the same. In constructing a receiverof this kind I employ a casing l, which is a hollow cylinder, to theends of which I secure iexible diaphragms 2 2 of thin vibrant materials,the said diaphragme being held in position by means of perforated caps 33, which may be screwed upon the ends of the cylinder, so as to clampthe said diaphragm in position at their edges, leaving their entirecentral p0rtions free to vibrate. Within the casing l I mount a suitablecore which is made up of a cylindrical portion 4, which is surrounded bya coil of wire, as 5. Vithin the cylinder 4 are arranged a series ofmagnetic bars, as 6 6, which are preferably secured at a pointintermediate of their length, as at 7, within the cylinder 4. Forholding these magnets in place I usually employ a block or piece 8,having a series of apertures formed therein adapted to receive the saidmagnets. The block 8 is also provided with an opening, preferably at thecenter, as at 9, so as to permit the air to pass freely from one side ofthe block to the other, according to the action of the diaphragms at theend of the receiver, the said diaphragms being polarized and movingsynchronously. This affords an opportunity to secure a column of airbetween the 'diaphragms in such a manner as to aid in their actingentirely in unison with each other, and thereby increase the power ofthe sound which they reproduce. The bars or rods 6 6 are preferablypermanent magnets and have their outer free ends located at a pointWithcylinder 4 to points near the center thereof,

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as indicated by the lines 10 10 of Fig. 1. The cylinder-core ispreferably formed of sol' t iron, so that it may be readily magnetizedand demagnetized under the action of electrical impulses passed throughthe coil 5, surrounding the same. By slitting the ends of the cylinder,as just described, a series of electromagnets are formed, which extendparallel with the permanent magnets for a considerable distance andstrongly attract the same when the said cylinder is magnetized. Theaction of the magnets upon the diaphragms forms a very important featureof the present invention, for they cause a warping or vibrating of thesaid diaphragme in moi'e than a' single wave. This action of the magnetupon .each diaphragm is clearly illustrated in Fig. 2 of the drawings,where it will be seen that two or more waves or bendings of thediaphragm may be produced by the said magnets. Such concentric wavesproduced in the diaphragms in response to impulses sent over thetelephone-line operate to greatly improve the strength and clearness ofthe reproductions of the said receiver. From the drawings it will beseen that when the cylinder 4 is magnetized under the actionof the coils5 the permanent magnets 6 6 will be dared outwardly toward the poles ofthe said cylinder, their outer ends being moved away from the center ofthe diaphragm and arranged in concentric circles nearer to the peripherythereof, so that the series of waves in the said diaphragm will becorrespondingly produced. I Iind in practice that this co'nstructionmakes it possible to distinctly reproduce the slightest sound orimpulses which may be enteredv at the transmit-ter of thetelephone-line.

The coil 5 is made up of a winding of wire suitably insulated, andtheends of the coil are connected directly with the line-wires 1l 11. Areceiver of this kind works admirably with a ground-circuit, so that oneof the said wires 11 may be connected directly with the ground. When thereceiver is employed upona line using one of my improved transformers ormagnozines, the said coil 5 is connected with the secondary winding 12of the said transformer through the line-wire 11, as illustrated in Fig.8 of the drawings. The primary winding of the said transformer 13 visconnected with a receiver 14 and a battery or other source of electricalenergy, as 15. The induced currents therefor of said transformer 13 willbe passed through the coil 5 for magnetizing or demagnetizing the coreof the receiver.

In winding the coil 5 I preferably accomplish it in such a manner as toreduce the resistance of the said core to the line-current withoutdiminishing the power of the coil. This is done, as illustrated in thedrawings, by reducing the winding to a minimum at a point opposite tothe neutral portion of the coil, as at 16, the winding increasing inthick` ness toward the ends of the coil opposite the poles thereof,where it attains its full size.

As described thus far the receiveris doubleended and is provided withtwo diaphragms operating at each end of the same. Thein' vention,however, is applicable to a receiver employing a single diaphragm, aswill be seen by reference to Figs. 5, 6, and 7 of the drawings. In thisconstruction a receiver formed of a hollow casing 17 of the usual formis employed, one end of which is enlarged, as at 18, to receive thediaphragm 19,

which is held in position by the perforated nets or rods 24 24, whichare arranged within the cylinder 2l and are secured and spaced at theirrear ends within the end of the cylinder 21 by means of a spacing-block25. The magnets 24 24 extend beyond the open end of the cylinder 21 andto points quite close to the inner surface of the diaphragm 19. In thisform of receiver I also preferably empio)7 a central magnet or rod 26,which is adjustably secured in position at the rear of the receiver andextends throughout the core and to a point near the diaphragm 19. Therod 26 is preferably split at its ends to form several reduced endportions, as seen in Fig. 7 of the drawings, the split portion extendingopposite to the neutral portion of the coil 23. The rear end of themagnet 26 extends through the plate 25 and through the end of thereceivercasing 17, its projecting end portion being screw-threaded andadapted to receive an adjusting-nut 27 and a clamping-nut 28. By thismeans the proximity of the magnet ends may be adjusted with relation tothe diaphragm 19. I preferably form the block 25 of soft iron, so thatthe sides of the pipe 2l and the magnets 24 and 26 are made intohorseshoe-magnets under the iniiuence of the coil 23. The coil 23 isconnected by means of wires 29 29 with binding-posts 30 30, whichreceive and secure in place the ends of the line-wires 31 3l. The actionof the magnets upon the diaphragm 19, under the influence of the coil23, will be quite similar to.that heretofore described with respect tothe diaphragms 2 2. The use of the central magnet 26, however, will tendto draw to one side the center of the diaphragm and produce a stillgreater number of concentric waves in the diaphragm.

In using receivers of this kind I find that they are very sensitive tothe impulses received over the telephone-line and that they willreproduce the slightest sound or impulses taken in at the transmitterand will augment them, so as to be strong and distinct. The

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construction ot' the receiver is quite simple and can beincorporated inany telephon e-line and is not likely -to get out of order easily.

Having now described the invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. A receiver for telephones, comprising a casing, one or morediaphragms mounted therein, a core for operating` the diaphragmscomprising a series of magnets grouped about the axis of the receiverand capable of Haring outwardly at their ends and a coil surrounding thesame for engaging them, the coil being connected with the line-wires,the structure being such that the magnetswill produce a series ofvibrations in the diaphragm, according to the impulses received in thecoil, substantially as described.

2. A :receiver for telephones, comprising a casing, diaphragms mountedtherein, a core interposed between the diaphragms comprisingaseries ofmagnets grouped about the axis of the receiver and having their endsarranged in close proximity to the said diaphragms and free to bend inany direction, a coil for varying the position of said magnets and theiraction upon the diaphragms,said coil being connected with the line-wiresof the telephone, substantially as described.

3. A telephone-receiver having two diaphragms arranged at each endthereof, a coil interposed between the diaphragms, a core mounted in thecoil and consisting of a cylinder adapted to be magnetized anddemagnetized, a series of magnets adapted to be mounted in the cylinderand having their ends arranged close to the diaphragms, means forholding the magnets in position within the coil, whereby their outerends are free to vibrate,and means for passing acurrent through the coilfor varying the action of the magnet on the diaphragms,substantially asdescribed.

4. A receiver for telephones, comprising a casing, diaphragms secured ateach end thereof, a core located between the diaphragms comprising aseries of magnets or rods extending to within a short distance of thediaphragms, a block for holding the same at their central point, acylinder of soft iron around the magnets and holding the block inposition 5o the said cylinder being slotted at its ends to form a seriesof projections parallel with the magnets and adapted to be magnetized ordemagnetized, a coil surrounding the said cylinder and adapted toreceive the current from 5 5 the line-wire, the said block forsupporting the magnets having an aperture whereby a column of air may bemaintained between the diaphragms for causing them to act in unison,substantially as described.

5.. Atelephone-receiver havinga diaphragm, means for magneticallyattracting the diaf phragm in concentric Waves, comprising a series ofmagnets having free .movable ends so that they may be spread out over agreater or less portion ofthe diaphragm accordin g to the strength ofthe current to which they are subj ected, and means for increasing ordiminishing the magnetic force of the same, substantially as described.y

6. Atelephone-receivercomprisinga casing, one or more diaphragms mountedtherein, means for vibrating the diaphragms in concentric circles,comprising a series of magnets capable of vibration at their ends so asto cover a large or small portion of the diaphragm according to thestrength of the current to which they are subjected, means for varyingthe position of the magnets with respect to the diaphragm and therebyaltering the shape of the vibrations produced in the diaphragms,substantially as described.

In testimony whereof I hereunto affix my signature in presence of twowitnesses.

' HANS LIEBREICH.

Witnesses:

JOHN L. FLETCHER, CAssELL SEVERANCE.

